Implementation and characterization of liquid-level sensor based on a long-period fiber grating MachZehnder interferometer

Hongyan Fu, Xuewen Shu, Aping Zhang, Weisheng Liu, Lin Zhang, Sailing He, Ian Bennion

Research output: Journal article publicationJournal articleAcademic researchpeer-review

71 Citations (Scopus)


An optical liquid-level sensor (LLS) based on a long-period fiber grating (LPG) interferometer is proposed and experimentally demonstrated. Two identical 3-dB LPGs are fabricated to form an in-fiber Mach-Zehnder interferometer, and the fiber portion between two LPGs is exposed to the liquid as the sensing element. The sensitivity and measurement range of the sensors employing different orders of cladding modes are investigated both theoretically and experimentally. The experimental results show good linearity and large measurement range. One of the significant advantages of such a sensing structure is that the measurement level is not limited to the length of the LPG itself. Also, the measurement range and sensitivity of the proposed LLS can be readily tailored for a particular applications.
Original languageEnglish
Article number5753906
Pages (from-to)2878-2882
Number of pages5
JournalIEEE Sensors Journal
Issue number11
Publication statusPublished - 2 Nov 2011
Externally publishedYes


  • Fiber sensor
  • liquid-level sensor (LLS)
  • long-period fiber grating (LPG)
  • Mach-Zehnder interferometer

ASJC Scopus subject areas

  • Instrumentation
  • Electrical and Electronic Engineering

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